class Solution {
public:
    string reverseStr(string s, int k) {
        for (int i = 0; i < s.size(); i += (2 * k))
        {
            if ((i + k) < s.size())
            {
                reverse(s.begin() + i, s.begin() + i + k);
            }
            else
                reverse(s.begin() + i, s.end());
        }
        return s;
    }
};
